Child sexual abuse issues are generally handled by state and local authorities, and not by the federal government. There are many sound reasons for this, including the relationship between the states, which generally have broad authority within their jurisdictions, and the federal government, which has constitutional limitations on its authority. As a result, the Department of Justice generally has no province over these matters.
If, however, a child is sexually abused on federal lands, such as a military base or Indian territory, the offender may be prosecuted under federal law in addition to, or instead of, state law (For more information, see Citizen's Guide to Federal Law on Sexual Abuse).